Corner gusset lock for containers of flexible material



June 2, 1959 M. WAGAMAN 2,839,102

CORNER GUSSET LOCK FOR CONTAINERS OF FLEXIBLE MATERIAL Filed April 29,1957 2 Sheets-Sheet 1 2 INVENTOR.

MERLE L. WAGAMAN 7' TORWEVS June 2, 1959 M. WAGAMAN 2,889,102

CORNER GUSSET LOCK FOR coummsas OF FLEXIBLE MATERIAL Filed April 29,1957 2 Sheets-Sheet 2 INVENTOR. MERLE L. WAGAMA/V BY 7 W Z TOP/VEVS2,889,102 Patented June 2, 1959 CORNER GUSSET LOCK FOR CONTAINERS OFFLEXIBLE MATERIAL Merle L. Wagaman, Lynwood, Califi, assignor toFibreboard Paper Products Corporation, San Francisco, Calif., acorporation of Delaware Application April 29, 1957, Serial No. 655,860

9 Claims. (Cl. 229-31) This invention relates to collapsible containersand more particularly to multi-cornered paperboard boxes or cartonsformed from a single sheet of flexible material, desirably paperboard,which is provided with an improved full gusset corner lock. Boxes of thetype to be described have become very popular and are widely used by'laundries to package various articles of clothing, as Well as bybakeries for covering and packaging cakes and other similar perishablefoods. The box of the present invention also is equally well adapted forwide use in other fields where paperboard boxes generally are employed.

Summarizing this invention, it has as its objects, among others, theprovision of a paperboard box having reinforced corner portions whichare strongly and securely retained against accidental separation afterthe box has been set up. Another object of this invention is theprovision of an improved corner gusset flap which will securely hold thebox in a set up position.

Yet another object of this invention is the provision of a box structurewhich may be used not only for the lower half of the box but which isalso adaptable for use as a telescoping cover of a box.

A further object of this invention is the provision of a corner flap fora box which has formed therein a marginal cut plus a score or fold linewhich impart increased flexibility and mobility to the corner flap tofacilitate setting up of the box.

A still further object of this invention is the provision of box cornerflaps having a double thickness of material which provides the corner ofthe box with added strength.

Further objects of this invention will become readily apparent from thefollowing description:

Generally, a box embodying this invention is of the common rectangularshape with upright side walls extending from a longitudinal cover panelwhich may be either the bottom of a box or the top on a closure for thebox. It should be understood, however, that the shape of the box may bevaried as desired and the box may be provided with any number of cornerswhich would adapt the box for any particular use. Each of the corners,however, preferably, but not necessarily, is of identical structure andthe purpose of this invention is to provide a secure lock for each ofthe corners which comprise the box.

The corner lock of this invention is substantially gusset or wedgeshaped, that is, in the form of a substantially triangular flap whichtraverses the corner area lying between adjacent side walls of the box.Each of the gusset flaps is folded along a diagonal or oblique hinge orfold line which divides the gusset flap into two similar sections. Byfolding along this diagonal or oblique hinge line, the gusset flap isformed into a two-ply corner locking flap which is intended to overlieand contact one of the adjacent side walls of the box. At the outerextremity of each gusset flap are positioned a pair of locking tabs,preferably identical in shape, which are intended to be lockinglyreceived in a slit formed in one of the side walls.

Boxes of the general character described have been known in the artpreviously but, in setting up all such boxes, it was often diflicult tosecure properly the locking tabs in the receiving locking slit withouttearing or enlarging the slit opening or deforming the locking tabs. Thebox of my device has been provided with additional means, which take theform of a marginal cut and a fold line, which fold line and cut impartadded mobility and flexibility to the gusset flap to facilitateinsertion of the locking tabs into the locking slit as the box is beingset up without danger of enlarging the slit or deforming the tabs.

It should be understood that preferably each of the corner sections ofthe box are identical and therefore only one corner has been illustratedin the drawings. Reference is now made to the drawings for a moredetailed description of the box and the improved corner gusset flapwhich is provided thereon.

Fig. l is a plan view of an outer corner portion of a paperboard blankfor setting up a box which embodies the preferred form of corner gussettype lock;

Fig. 2 is an isometric view of the blank corner portion of Fig. 1 in setup condition with the locking tabs of the gusset flap securely retainedin the locking slit formed in one of the side walls;

Fig. 3 is a side view of one corner of the box in set up positionshowing the locking tabs extending through the slit in the box sidewall;

Fig. 4 is a fragmentary horizontal section of a set up corner of a boxtaken in a plane indicated by line 44 in Fig. 3. This view shows theconstruction of the box when the gusset flap overlies the side wall withthe locking tabs inserted in the locking slit;

Fig. 5 is a top view of an intermediate step in setting up the box whichillustrates the added flexibility and mobility imparted to the gussetflap by means of the marginal cut and additional fold line formedtherein;

Big. 6 is a vertical longitudinal section through a corner of the boxtaken in a plane indicated by line 66 in Fig. 5. The box is shown in anintermediate position while it is being set up. The flexibility andmobility imparted to the gusset flaps by the marginal cut and additionalfold line are clearly illustrated;

Fig. 7 is a plan view of a fragmentary corner section of a blankillustrating a somewhat modified form of the improved gusset type cornerlock embodied in my invention;

Fig. 8 is a side view of the blank of Fig. 7 showing the modified cornerof the box in the set up condition;

Fig. 9 is a partial horizontal section of a modified set up box cornerembodying the features of Fig. 7 taken in a plane shown by line 9-9 inFig. 8. The corner of the box is shown in set up position;

Fig. 10 is a partial vertical section showing the inside of the modifiedbox corner in set up position taken in a plane shown by line 1010 inFig. 9. The engagement of the locking tabs with the locking slit and theinner face of the side wall is clearly shown.

In all embodiments shown, cuts are shown as solid lines, conventionalcrease lines are shown as dot-dash lines, while cut-score lines areshown as dashed lines. The relative lengths of the cuts in the cut-scorelines are indicated by the length of dashes shown.

Referring to Fig. 1, a portion of a box blank is shown which embodiesfeatures of this invention. The outer portion of the blank isillustrated. In a typical laundry box or bakery box of the typementioned previously four corner portions integrally connected would beutilized,

3 each of which desirably embodies the structure shown in Fig. 1.

However, depending on the use for which the box is intended, the numberof corners formed thereon may be varied as desired to meet a particularneed. It should be understood that the exact shape and size of the boxis relatively immaterial.

In Fig. l is shown a portion of a flat blank from which a box embodyingthis invention is intended to be set up. The blank portion shown in Fig.1 is intended to produce a conventional rectangular box, but it shouldbe understood that the corner structure would vary slightly dependingupon the desired shape of the finished box.

Each corner portion of the blank comprises a cover panel 2 having sideWalls 3 and 4 hingedly secured to intersecting margins thereof.Intersecting crease lines L are positioned between each of side walls 3and 4 and the adjacent margins of the cover panel 2 to which the sideWalls are secured to facilitate folding of the box into its set upposition. It should be noted that extensions of crease lines L run alongadjacent end margins of the side walls 3 and 4.

A full gusset or corner panel, generally designated 6, is interposedbetween and traverses the space lying between adjacent end margins ofside walls 3 and 4. This gusset or corner panel 6 consists of twosimilar sections 7 and 8. A diagonal or oblique fold or crease line 9divides the gusset corner flap 6 into the two similar sections 7 and 8just mentioned. This diagonal or oblique fold line 9 extends fromadjacent the point of intersection P of the two crease lines L towardthe outer extremity of the gusset panel which lies diagonally oppositesuch intersection point P.

Corner gusset panel 6, it should be noted, is of substantially wedge orroughly triangular shape in that a portion 11 thereof has been cut awayadjacent the end of the diagonal fold line 9. The cut out portion 11forms two locking tabs 12 and 13 which lie on opposite sides of saidfold line 9. On opposite sides of tabs 12 and 13 are cut out portions,18 and 19, of substantial V- shape, which are continuations of, andcommunicate with, enlarged cut away portion 11.

When side walls 3 and 4 of the blank are folded upright with respect tocover panel 2, corner panel 6 is automatically folded along crease line9, thereby forming a gusset locking panel comprising two similarsections 7 and 8 arranged in overlapping face to face relationship. Thepurpose and function of the folded sections of the corner gusset panelwill be more fully set out hereinafter.

In side wall 3 is formed a substantially L-shaped cut or locking slit 14which is located adjacent the end margin of side wall 3. L-shaped slit14 has oppositely directed cut portions which meet at an elbow portion15.

Extending inwardly from an outer margin of the cover gusset panel 6 isanother L-shaped cut 16. It should be noted that cut 16 extends for aportion of its length as a continuation of the crease line L whichseparates corner flap 6 from side wall 3. At a location spaced from theouter margin of the blank, however, the cut 16 has portion 16a whichveers inwardly into section 8 of gusset panel 6 to produce the L-shapedconfiguration described previously.

Extending from the inner end of cut portion 16a and preferablycommunicating therewith is an additional or auxiliary fold line 17 whichalso is formed in section 8 of corner flap 6. Fold line 17 extendsobliquely to a point adjacent the point of intersection P of the creaselines L but desirably, though not necessarily, stops short thereof. Thepurpose of cut 16 and additional crease or fold line 17 will be madeclear as this specification continues.

Desirably, although not necessarily, both crease or fold lines 9 and 17take the form of cut-score lines. The

relative lengths of the cuts formed in the cut-score lines may be variedslightly to meet particular needs. As illustrated in Fig. l, the outerportion of cut-score line 9 has cuts formed therein which aresubstantially longer than the cuts formed in the inner portion ofcut-score line 9. In addition, the extension of crease line L which liesbetween side wall 3 and corner panel 6 similarly may be formed as acut-score line although this is not necessary in all embodiments of thisinvention. For many uses, a conventional crease line will be adequate tofacilitate folding of corner panel 6 relative to side wall 3. Thepurpose of such cut-score lines is to facilitate proper folding of theblank into the finished box at the desired locations with a minimum ofeffort and without danger of deforming the blank at a location otherthan along the cut-score lines.

As mentioned previously, the corner panel 6 is roughly of wedge ortriangular shape due to the cut out portion 11 which has been removedfrom the outer margin of the corner panel. However, pointed portions 21and 22 of corner panel 6 are retained in the panel so that the cornergusset panel 6 will have portions lying flush with the upper edge ofside wall 3 when the box is set up. See Fig. 2. It is evident,therefore, that point P of the intersecting crease lines L forms theapex of such triangular corner panel 6. The fold line 9, as is clearlyshown in Fig. 1, extends from such point P diagonally across cornerpanel 6 to an outer margin thereof. Locking tabs 12 and 13 arepositioned at a location adjacent the outer end of fold line 9 and arehingedly connected to each other along such fold line.

After the side walls 3 and 4 have been folded into an upright positionextending from cover panel 2, the corner gusset panel 6 automatically isfolded into two sections 7 and 8, each of which has face to faceoverlapping engagement with the other. In such folded position, lockingtabs 12 and 13 also are in abutting face to face relationship. Thisintermediate position of the folded corner panel 6 is clearly shown inFigs. 5 and 6 of the drawings.

Referring to Fig. 5, a corner of the box is shown with the side walls 3and 4 in substantially upright position with the folded corner panel 6ready for bending against side wall 3 for subsequent sliding insertioninto the L-shaped cut or locking slit 14.

It is at this stage of the setting up operation that th: lockconstruction of. this invention overcomes the prob lems encountered withfull flap corner gusset locks in boxes heretofore employed. In suchother boxes it is often necessary to deform the ends of the locking tabsor to inadvertently tear or otherwise enlarge the locking slit formed inthe side wall so that the locking tabs may be inserted therein. In thisinvention, however, any tearing or deformation of the locking slit, aswell as any deformation of the locking tabs, is completely eliminated.

Such deformation of the locking slit 14 or locking tabs 12 and 13 isprecluded because of the provision in the corner flap 6 of the cut 16and additional fold line 17. Such cut and fold line impart the neededmobility and flexibility to the folded corner flap 6 so that the face toface locking tabs 12 and 13 may be easily inserted into receivinglocking slit 14. The mobility imparted to corner flap 6 by cut 16 andfold line 17 is clearly illustrated in Figs. 5 and 6.

As shown in Fig. 5, the fold line 17 which extends into section 3 of thecorner flap 6 permits the folded corner flap to be additionally bentalong such fold line 17 so that the folded corner flap may be urgedslightly outwardly away from the side wall 3 so that the locking tabs 2and 13 readily may be manipulated into engagement with the locking slit14. However to allow the folded corner panel 6 preliminarily to be urgedaway from the side wall 3 it also is necessary to form cut 16 along theconnecting fold line extension between the corner flap 6 and side wall 3and inwardly into section 8 of corner flap 6 as indicated at 16a.

The L-shaped cut 16 allows side wall 4 to remain slightly inclinedrelative to the cover panel 2 and spaced from adjacent side Wall 3 whilethe locking tabs 12 and 13 of corner panel 6 are held substantially flatagainst cooperating side wall 3. When in such position, the locking tabsthen readily may be slid along side wall 3 until they are engaged withand securely held within locking slit 14 in the position shown in Figs.2 through 4.

In this respect it is never necessary to bend or twist the locking tabs12 and 13 or to otherwise destructively deform either the tabs or theslit 14 while the tabs are being inserted therein. To allow insertion ofthe tabs it only is necessary .to press the L-shaped portion of sidewall 3 formed by slit 14 slightly out of the plane of the wall to allowthe tabs to he slid through the slit.

As shown in phantom lines in both Figs. 2 and 3, the locking tabs, afterinsertion into locking slit 14, have their edges securely engaged withan edge of locking slit 14 with the outer extremities of the tabspositioned against the inner surface of side Wall 3. Figs. 2 and 3 alsoshow that the V-shaped cut out portions 18 and 19, adjacent locking tabs12 and 13 respectively, are securely and tightly engaged with the elbowportion 15 of the L-shaped slit 14 formed in side wall 3. In this mannerthe tabs are securely retained in the locking slit 14- and the box isretained with each of its corners in set up position. The dimensions oftabs 12 and 13 relative to slit 14 are such that the tabs are readilyslidable into slit 14 and produce a tight fit therein without permittingunwanted excess shifting movement of the tabs in the slit.

Fig. 2 also clearly illustrates the reinforced corner portions producedin a box embodying the present invention. As can be seen, the similarsections 7 and 8 of the corner flap 6 are folded into overlapping andcontacting engagement with a portion of the side wall 3. The box,therefore, at its corners has substantially a three-ply thickness whichgreatly increases the strength of the box due to the strut-likereinforcing action produced by such three-ply thickness. The increasedcorner strength allows a plurality of boxes to be stacked one on theother without danger of collapsing the lower boxes in the stack.

It should be understood, however, that the new and useful corner gussetlock described herein is not limited solely to the bottom portion of apaperboard box. The invention described is equally applicable in formingthe top or cover of a box member which is intended to be telescopicallyreceived over a similarly formed bottom portion of a box.

The particular shape of the gusset corner lock de scribed herein is suchthat a box embodying this invention is especially adaptable to be set upby hand, especially when the gusset lock is utilized on boxes of substantial size, such as laundry boxes or large bakery boxes.

However, under certain situations, a box embodying this gusset lock moredesirably may be set up mechanically in a suitable setting up machine.

It should also be pointed out that the flexibility and mobility impartedto the gusset panel of this invention is of particular importance whenthe box is formed from relatively heavy gauge paperboard. Such heavypaperboard does not possess the inherent resiliency and flexibilitynecessary to allow interengagernent of tab and slit means in the absenceof gusset panel flexing means. The flexing means disclosed hereinbecomes necessary to allow such interengagenment to be accomplished insuch a case without danger of tearing the slit or deforming the lockingtabs.

Referring now to the modification of this device which is shown in Fig.7, it should be understood that the component parts of the blank shownare substantially similar to the parts previously enumerated indiscussing Fig. 1.

6 t t t Similar reference numerals have been used for each of the partsand only a prime has been added to each of the reference numerals todistinguish the pants of Fig. 7 from the parts of Fig. 1.

As readily can be seen, the basic blank shown in Fig. 7 is substantiallyidentical to the blank previously discussed with reference to Fig. 1.The only distinction in Fig. 7 over Fig. 1 lies in the fact that thelocking tabs 12' and 13 are not hingedly connected along diagonal foldline 9'. As is shown in Fig. 7, tabs 12' and 13 are separated by a cutout portion 23 which is part of the enlarged cut out portion 11'. Thiscut out portion has been designated 23 and extends between locking tabs12' and 13' to a point adjacent the end of the diagonal fold line 9which extends inwardly to the point P, the point of intersection of thecrease lines L.

The blank of Fig. 7 is similarly provided with an L-shaped cut 16 whichextends from an outer margin of the blank along the extension of creaseline L between side wall 3 and corner gusset flap 6'. From the inner endof cut 16' an additional fold line 17 extends to a point adjacent thepoint P.

The setting up operation for the blank of Fig. 7 is identical with theoperation previously disclosed with reference to setting up the blank ofFig. 1. The necessary flexibility and mobility are imparted to thegusset panel of the blank of Fig. 7 by cut 16' and additional fold line17.

In certain situations it is more desirable to have the locking tabs ofthe improved gusset corner panel slightly spaced from each other, ratherthan integrally connected along a diagonal fold line, and for thispurpose the modification of Fig. 7 has been devised, The lock producedby using the embodiment shown in Fig. 7 is no less secure than the oneillustrated in Fig. 1, however.

Although duplicate locking tabs have been illustrated on bothembodiments of the gusset flap shown in the drawings, it should beunderstood that under certain circumstances a single locking tab wouldbe sufiicient. However, double tabs, folded in face to face relationshipas illustrated, increase the strength of the box corner and moresecurely retain the box in set up condition. Double locking tabs,therefore, are more desirable on most boxes which incorporate a gussetflap of the type herein disclosed.

It should be understood that modifications of the invention disclosedherein may be made without departing from the general scope of theinvention. Having now made a full disclosure, what I claim as myinvention is:

1. A blank adapted to form a multi-cornered container wherein acomer-forming section of said blank comprises a cover panel, side wallpanels hingedly secured along intersecting crease lines to adjacentintersecting margins of said cover panel, a gusset panel traversing thespace between said side wall panels and hingedly connected thereto alongextensions of said intersecting crease lines, an oblique fold lineformed in said gusset panel and extending toward the point ofintersection of said crease lines, lock tab means formed on said gussetpanel adjacent the outer end of said oblique fold line, another foldline in said gusset panel extending outwardly from adjacent said pointof intersection and positioned between said oblique fold line and one ofsaid crease line extensions, and a locking slit formed in the side wallpanel to which said gusset panel is connected along said last mentionedcrease line extension for receiving said lock tab means whereby saidblank when set up has the section of said gusset panel which includessaid other fold line in face to face engagement with said last mentionedside wall panel and said lock tab means interengaged with said slit.

2. A paperboard blank, adapted to form a multieornered box, having aplurality of corner portions, a corner portion comprising a cover panelhaving intersecting margins, a side wall panel secured to one margin ofsaid cover panel, another side wall panel secured to an adjacent marginof said cover panel, a gusset panel interposed between adjacent endmargins of said side wall panels, intersecting fold lines extendingbetween connected margins of said cover panel and said side wall panels,extensions of said fold lines extending between said gusset panel andthe end margins of said side wall panels, lock tab means formed on saidgusset panel, an oblique fold line provided in said gusset panelextending between the point of intersection of said first mentioned foldlines and said lock tab means, another fold line provided in said gussetpanel between said oblique fold line and one of said fold lineextensions and extending outwardly from adjacent said point ofintersection to a point spaced from one side of said lock tab means, acut extending inwardly from an outer margin of said gusset panel andoperatively communicating with said another fold line, said cut and saidanother fold line imparting flexibility and mobility to said gussetpanel during setting up of said box, and a locking slit formed in one ofsaid side wall panels adjacent said gusset panel for receiving said locktab means when said box is in set up condition.

3. A multi-cornered box, formed from a flat blank, wherein a cornerportion comprises a cover panel, two side walls extending upright fromsaid cover panel, a corner flap connected to the end margin of each ofsaid side walls, said corner flap being doubled into similar sectionsalong an oblique fold line extending outwardly from the corner of saidcover panel, locking means on said corner flap adjacent the outer end ofsaid oblique fold line, a cut extending inwardly into said corner flapfrom the outer margin thereof, another fold line provided in said cornerflap between said oblique fold line and the connection between saidcorner flap and one of said side walls, said another fold line extendingfrom adjacent the end of said cut to a point adjacent said corner ofsaid cover flap, said cut and last mentioned fold line allowing flexingof said corner flap while precluding damage thereto during setting up ofsaid box, and a locking slit formed. in said one of said side walls inwhich said locking means is securely retained after said corner flap hasbeen bent to overlie a portion of said one side wall.

4. A multi-cornered paperboard box wherein a corner is formed by abottom panel, a pair of adjacent side walls extending upwardly from saidbottom panel, one of which has a locking slit therein, and a gusset typecorner fiap connected to each of said side walls and overlying part ofsaid one side Wall, said corner flap comprising similar sections foldedface to face along an oblique hinge line which traverses said cornerflap, lock tabs positioned face to face adjacent the outer end of Saidoblique hinge line, a marginal cut extending into one section of saidcorner flap, another hinge line provided in said corner flap betweensaid oblique hinge line and the connection between said corner flap andsaid one side wall, said another hinge line extending from adjacent theinner end of said marginal out toward said oblique hinge line, saidcorner flap being folded against said one side wall so that the sectionof said corner flap which contains said cut and said another hinge linecontacts said one side wall with said lock tabs securely retained insaid side wall locking slit.

5. A multi-cornered box wherein one of the corners consists of a bottompanel, two adjacent and angularly related side walls extending from saidbottom panel with a locking slit cut in one of said side walls, and acorner flap connected along crease lines to said side walls andoverlying said one side wall; said corner flap comprising two similarflap sections folded face to face along an outwardly directed hinge linewhich obliquely traverses said corner flap, locking means formed on saidcorner flap adjacent the outer end of said outwardly directed hingeline, and a narrow elongated cut extending into one of said flapsections from an outer margin of said corner flap, thereby partiallysevering said corner flap from said one side wall, said out including aportion which extends angularly into said one flap section relative toand from the crease line connecting said corner flap to said one sidewall in the general direction of said outwardly directed hinge line,said cut imparting mobility to said one flap section to facilitatesetting up said box so that said folded corner flap may be positionedaway from said one side wall along the length of said cut preliminary topositioning said corner flap in engagement with said one side wall sothat said locking means may be inserted in said locking slit withoutdamaging either; and said locking means extending into and beingsecurely retained in said locking slit to maintain said box in set upcondition with said one flap section in face to face contactingengagement with said one side wall.

6. In a corner lock on a container having a cover panel, a pair ofadjacent side walls hingedly connected to said cover panel, a fullgusset lock flap hingedly connected to the adjacent ends of said sidewalls along crease lines and having an oblique fold line enablingsections of said gusset flap to be folded in overlapping relationshipwhen said side walls are set up, locking means on said flap, one of saidside walls having cooperable locking means for engagement with thelocking means on said flap; and means to enable flexing of said gussetflap to facilitate inter-engagement of said locking means withoutdamaging the same comprising an auxiliary fold line on one of said flapsections extending between said oblique fold line and the crease lineconnecting said gusset fiap with the side wall having the cooperablelocking means, and a narrow elongated marginal cut having a firstportion forming a substantial continuation of said latter mentionedcrease line and a second portion extending from said first portiontoward said auxiliary fold line on said one fiap section, said gussetflap being partially severed by said out from said last mentioned sidewall whereby during setting up said container said gusset flap whenfolded along said oblique fold line may be positioned away from suchside wall along the length of said second cut portion and said one flapsection may be folded along said auxiliary fold line so that said gussetpanel and the locking means thereon may be brought into engagement withthe locking means on such side wall without damaging either of saidlocking means.

7. A blank adapted to form a multi-cornered container wherein a cornerforming section thereof comprises a cover panel, a pair of side wallpanels hingedly connected along intersecting crease lines tointersecting margins of said cover panel, and a gusset panel traversingthe space between said side wall panels and hingedly connected theretoalong extensions of said intersecting crease lines, an oblique fold lineprovided in said gusset panel extending from adjacent the point ofintersection of said crease lines toward an outer extremity of saidgusset panel, lock means on said gusset panel, and cooperable meansprovided on one of said side wall panels for engagement with said gussetpanel lock means when said container is set up, an auxiliary fold linein said gusset panel extending outwardly from adjacent said point ofintersection and positioned between said oblique fold line and one ofsaid crease line extensions, and an L-shaped marginal cut extendinginwardly from an edge of said blank and having a first portion thereofforming a substantial continuation of said one crease line extension anda second portion thereof extending into said gusset panel from the innerend of said first cut portion and terminating adjacent the outer end ofsaid auxiliary fold line, said auxiliary fold line and L-shaped cutimparting mobility and flexibility to said gusset panel whereby uponsaid gusset panel being folded along said oblique fold line andpositioned in contact with said one side wall said gusset panel lockmeans readily may be engaged with said cooperable means withoutdeforming or tearing either said lock means or said cooperable means.

8. A corner lock for a set-up container comprising a cover panel, a pairof adjacent side walls hingedly connected to said cover panel andextending substantially upright therefrom, a gusset panel hingedlyconnected to adjacent ends of said side walls along intersecting creaselines and having an oblique fold line extending from adjacent the pointof intersection of said crease lines toward an outer extremity of saidgusset panel, said gusset panel being folded along said oblique foldline to provide similar gusset panel sections positioned in face to faceengagement, lock means on said gusset panel and cooperable means on oneof said side walls with which said gusset panel lock means isinterengaged to maintain said container corner in set up condition; andmeans imparting mobility and flexibility to said gusset panel tofacilitate interengagement of said lock means and cooperable meanswithout distortion or destructive tearing of either of said meanscomprising an auxiliary fold line on one of said gusset panel sectionsbetween said oblique fold line and the crease line connecting saidgusset panel with said one side wall, and an L-shaped cut having a firstportion thereof extending inwardly from an outer margin of saidcontainer as a substantial continuation of said last mentioned creaseline, a second portion of said cut extending from the inner end of saidfirst cut portion into said one gusset panel section and terminatingadjacent the outer end of said auxiliary fold line whereby said out andauxiliary fold line are cooperable to impart said mobility andflexibility to said gusset panel; said gusset panel being folded so thatsaid one gusset panel section including said second cut portion and saidauxiliary fold line overlies and contacts said one side wall and ismaintained in such overlying relation by said interengaged means.

9. A blank adapted to form a multi-cornered container wherein a cornerforming section thereof comprises a cover panel, a pair of side wallpanels hingedly connected along intersecting crease lines tointersecting margins of said cover panel, a gusset panel traversing thespace between said side Wall panels and hingedly connected thereto alongextensions of said intersecting crease lines, gusset panel lock meansdefined by generally V-shaped cut outs in said gusset panel andcooperable means on one of said side wall panels interengageable withsaid lock means for maintaining said container set up, and a narrowelongated cut independent of said V-shaped cut outs extending inwardlyfrom an edge of said blank, a first portion of said cut forming asubstantial continuation of one of said crease line extensions and asecond portion thereof extending angularly relative to said one creaseline into said gusset panel from the inner end of said first cutportion, said elongated out imparting flexibility and mobility to saidgusset panel so that the same may be positioned away from said one sidewall panel along the length of said second cut portion as said lockmeans on said gusset flap is engaged with said cooperable means on saidone side wall whereby setting up of said container without resultantdistortion or damage to said lock means or said cooperable means duringinterengagement thereof may be effected.

References Cited in the file of this patent UNITED STATES PATENTS459,543 Clark et al. Sept. 15, 1891 1,111,552 Allers Sept. 22, 19141,190,797 Powell July 11, 1916 1,567,594 Hitzert Dec. 29, 1925 1,947,199Goodnow Feb. 13, 1934 2,443,431 Ringler June 15, 1948 FOREIGN PATENTS80,563 Sweden May 29, 1934

